Circuit breaker



1 July 14, 1936. l.. J. LINDE CIRCUIT BREAKER Filed Feb. 5, 1955 2 Sheets-Sheet 1 Inventor:

July 14, 1936. L. J. LINDE i CIRCUIT BREAKER Filed Feb. 5, 1955 2 Sheets-Sheet 2 Inventor Leonard J. Linde,

His ttorheg Patented Julyy 14, 1936 l UNITED STATESA PATENT oFFIcE 2,047,829 cmourr nimma Leonard J. IA'n eral Electric York Application February 5,

de, Aldan, Pa.,

Company, a corporation of New assigner to Genf 1935. serial No.. 5,036

10 Claims. (Cl. 200-116) It has heretofore been proposed to employ multipolercircuit breakers in installations of this type 1n which a single operating mechanism is proautomatically responsive to current conditions in the individual circuits. However, much is yet to be desired in a cireuit breaker of'this type which is compact and rugged and which will quickly inone Contact to open circuit position upon the occurrenccr of abnormal current conditions, the manually operable mechanism and the automatic andto produce a compact and sturdy arrangement More specically, I 'provide a multlpole circuit'breaker provided with a plurality of pairs tacts be is reliable in its operaof relatively movable contacts, each pair of conmechanism of the circuit breaker.

Referring to the drawings, I ,have shown my invention in one form as applied to a multipole circuit breaker base I formed of are respectively provided with the insulating barriers I8 and I9 arranged substantially in alignment withk the barriers I6 and I1. The circuit for each pole of the circuit breaker is substantially the same and extends from one of the terminal members I I through the interrupter device I3 across the operating mechanism by way of a iiexible conductor 20 and through the trip device I5 to one of the terminal Each of the circuit interrupting' devices I3, which are of the type described and broadly claimed in a ccpending application of Ludwig S.

n members I2.

' Walle Serial No. 667,856, filed April 25, 1933, en-

titled Circuit break and assigned to the same `a U-shaped member assignee as the present invention, comprises a compression chamber which includes a cylindrical casing 2| of suitable pressure resisting material, enclosing a xed contact 22 and a reciprocally movable contact 23. A cylindrical liner 24 of kerosene-free fiber is arranged within the cylinder 2| surrounding the contacts and in order gas tightly to seal the fixed contact end of the cylinder 2| and to provide a rigid support for the fixed contact, a sealing cup 25 of suitable material such as soft copper, a pair of insulating bushings 26 and 21 and an insulating washer 28 are provided. It will be apparent that when the nut 29 is tightened down on the threaded end SII-of the iixed contact, the insulating members 26, 21 and 28 will be wedged tightly together by an enlarged shoulder 3| formed on the fixed lcontact 22 and by a wedge-shaped flange 32 on the cylinder 2| to form a gas tight closure vfor this end of the compression chamber and a rigid support for the xed contact 22.

The movable contact end of the compression chamber is provided with a cylindrical cap 33 which threadedly engages the cylinder 2| and is provided with a sealing gasket 34. Supported by the cap 33 is a plug 35 in which the movable contact 23 is slidably journaled. In order to provide for snap action of the movable contact 23 while at the same time substantially sealing the compression chamber, avpair of sealing washers 36 of leather or other suitable material are provided, and the movable contact 23 is provided with a. shoulder 31 arranged. to engage a conical valve seat 38 formed in the cap 33 gas tightly to seal this end of the compression chamber when the movable contact is in open circuit position. The particular features of the compression chamber and the sealing means therefor .form no part of the present invention and are fully described and claimed in another application of Ludwig S. Walle, Serial No. 4,448, led Feb. l, 1935, entitled "Circuit breakers which application is assigned to the same assignee as the present invention.

In order simultaneously to operate all of the movable contacts 23 between open and closed positions, I provide an insulated crossbar 39 which extends across all of the poles of the circuit breaker and is journaled at its ends in the bearings 40 carried by the base I0. Each of the movable contacts 23 is connected to the crossbar 39 by a resilient lost-motion connection which includes a pin 4| supported by the legs of 42, the yoke portion of which comprises a frame 42a which surrounds the crossbar 39. Each of the pins 4| extends through a slot 43 in a block 44 xedly secured to the associated movable contact 23. As shown in Fig. 2, each of the movable contacts 23 is drilled to accommodate a spring 45 one end of which bears against the contact 23 and the other end of which is engaged by the pin 4|.

In a copending application of Charles H. Hill, Serial No. 18,127, i'lled April 25, 1935, entitled Circuit breakers, which application is assigned to the same assignee as the present invention, there is described and claimed a circuit breaker having an operating mechanism comprising a contact operating toggle, one link of which cornprises a three-point crank lever, overcenter spring means for rotating the crank to make and break the toggle. and a tripping arm biased for movement to break the toggle independently of the overcenter spring means. The invention disclosed in the above application was made by the said Charles H. Hill prior to my invention and I., therefore, do not herein claim anything shown or described in that application, which is to be regarded as prior art with respect to the present invention.

My improved operating mechanism for actuating the crossbar 39 to move all oi.' the contacts 23 between open and closed circuit position is arranged adjacent the movable contact end of the interrupting devices I3 on a frame which comprises a pair of spaced supporting walls 46 carried by a supporting block 41 which is fastened to one of the cylinders 2| by the screws 48. As may be seen best by reference to Fig. 6, each of the supporting walls 46 includes an elongate portion extending along the cylinder 2| and provided with slots 49 and 59 and a laterally extending portion which overhangs the movable contact ends of the cylinder. The slots 49 are elongate as shown and serve as guides in a manner to be fully described later.

Carried by the overhanging portion of the supporting walls 46 is a pivot pin 5|, the outwardly extending ends of which pivotally support a U-shaped operating member 52 which is provided with an insulating handle 53 arranged to extend through a suitable aperture 54 in the circuit breaker cove'r 55, as shown best in Fig. 2. A second pivot pin 56 extends between the portions of the supporting walls 46 which nest within the legs of the U-shaped operating member 52 and pivotally supports a pair of parallel switch operating' arms 51,;the other ends of which carry an operating pin 58. Extending between the arms 51, I provide a pair of bracing members 51a. These braces are not shown in Fig. 6 in order to simplify the drawings. Pivotally supported on a third pivot pin 59 carried by the frame walls 46, I provide a pair of three-point or substantially triangular toggle links 6|! each of which is provided with a slot 6| through which the respectiveends of the operating pin 58 extend. Connected to each 'of the three-point toggle links 60 is one of a second pair of toggle links 62, the adjacent opposite ends of winch links pivotally engage a p in 63 carried by the legs of a U-shaped member 64 the yoke portion of ivghich surrounds and is secured to the crossbar In order to make and break the toggles which comprise the links 66 and 62, to move the crossbar 39 and the movable contacts connected thereto between open and closed circuit positions with a snap action, I provide a pair of overcenter spring devices connected between the operating pin 58 and the U-shaped operating member 52. Each of the overcenter spring devices, as shown best in Fig. 6. comprises a U- shaped frame 63a pivotally connected to the operating pin 58 adjacent the open end of the U, and a yoke member 64a pivotally carriedby one of the pins 65 which extend outwardly from the U-shaped operating member 52. `Extending from the yoke member 64a is a pair of plunger rods 66 which slidably extend through the end of the U-shaped frame 63a, each oi.' the plungers being surrounded by a compression spring 61 the adjacent ends of which bear against the end of the vU-shaped frame and the other ends of which bear against a plate 68carried by the plungers, portions of the plate 68 being cut away as indicated by the reference numeral 69 to slidably engage the legs of the U-shaped frame 63a which serve as guides therefor. It will be apparent that the compression springs 61 are arranged norpivot pin 59 to mally to hold the yoke member 64a. in engagement with the end of the U-shaped frame 83aA and to resist relative movement therebetween.

the arrangement being such, that the device acts as a strong tension spring connected between the operating member 52 and the operating pin 58.

In Fig. 2 I have shown the circuit breaker in its closed circuit position, and it will be apparent that when the insulated handle 53 is moved downovercenter relative to the pivot pin 56, the operating pin 58 which is carried by the switch operating arms 5l will be moved downwardly with a snap action, thereby moving the three-point toggle links 6|| about the i thereto to the open circuit position shown in Fig.

mostposition shown in Fig. 2 will be effective to n rIt will of course be apparent that the toggle making and breaking force exerted by the overcenter spring devices will depend not only upon kthe strength of the the walls 45 and is springs 6l but upon the displacement of the line of action thereof from the pivot pin 56. By disposing the operating member 52 and the switch arms 51 in partially overlapping relation on the spaced pivot pins 5| and- 56, not only is a more compact structure effected but ralso a relatively large displacement of the theioperating member 52.

The circuit breaker is also adapted for automatic operation to open the circuit upon the occurrence of predetermined abnormal current conis'substantially U-shaped, as shown best inFig. 6, and is pivoted adjacent the open end of the U on the'J extending ends o1' the U' being provided with the portions 'I4 which respectively extend laterally on opposite sides of the pivot. As shown best in Figs. land 2, the ytripping springs are disposed between the elongate portions of the frame walls 46 with the ends thereoil which arey adjacent the tripping membery 18 engaging a xed crossbar 'I8 supportedy inthe slots 58 and the ends which are remote from the tripping member 'I8 engaging a movable crossbar 11 slidably suported in the slots or guides 49 with\its ends extending therethrough and respectively connected to a pair of'oper'ating straps '18.5Each of the straps 18 extends along one of v provided with va hook-shaped end`|8 whichv engages one of a pair of pins 88 extending from the portion 14 oi' the tripping member '|8. f

y yIt be observed that each of the crossbars 16and Il is provided with a pair of ngers 8| whichex'tend a short distance into the respective and 'l5 break. the toggles and operate the v ycrossbar 39 and the movable contactsconnected pin 5|, each ieg of the ends of the tripping springs 1| to guide the same. and that each of the springs is surrounded by a supporting cylinder 82 which cooperates with the ngers 8| to maintain the tripping springs 1| in proper alignment between the crossbars 16 and Any suitable trip device may be provided for releasably latching the tripping member 'i8 in its normal position against the bias exerted by the tripping springs 1| and for releasing the member upon the occurrence of abnormal current conditions. The force exerted by the tripping springs 1 I, however, is of considerable magmtude and accordingly, I prefer to use a rugged trip device of the type described and claimed in a copendlng application of John L. Lappin, Serial No. 4,659, filed Feb. 2 1985, entitled rCircuit breakers, which application is assigned to the same assignee as the present invention.

This trip device I5 may be described for the purposes of the present application as comprising a subbase 83 suitably fastened to the circuit breaker base I0, the before-mentioned insulating barriers I9 being formed integral therewith.- Supported centrally of the subbase 83 is a frame comprising the spaced walls 84 between which are supported a latch plate 85 pivoted at 85a, a U-shaped impactmember 86 pivoted at 86aand a U-shaped reset member 8l `pivoted at 81a. 'I'he latch plate 85 carries the previously referred to latch ringer l2. and the yoke portion of the U'-r shaped impact member 86 is overturned to provide a striking rsurface 88 for engaging a portion of the latch plate 85 nested therein. Each leg of the impact member 88 carries a pin 89 extending through a slot`98 in one of the supporting walls 84 and arranged to engagera cam linger 9| provided on the U-shaped resetl member 81, the yoke portion of which is interposed in the path of the tripping member 10.

Suitable springs 92 are provided for operating ethe impact member 85 about its Ipivot 86a in a counterclockwise direction to strike the latch plate 85 a hammerlike blow and thereby move the latch nger l2 to-release the tripping member lll, and a pair of resetting springs 93 are arranged to operate the reset member 81 about its pivot 81a in a counterclockwise direction to return the impact member 88 to the position shown in the drawings after each operation thereof to striking position. 'I'he impact member 86 is normally heldy in `the position shown in the drawings Aby a trip bar 94 which extends across the three poles of' the circuit breaker and is pivoted adjacent its ends lon a pin 94a, the trip bar being normally biased'by a spring 95 to engage a iinger 96 carried by the impact member.

Associated with each pole of the circuit breaker is a thermal and a magnetic device for moving the trip bar 94 about its pivot to release the impact member 86. Each thermal device comprises a bimetallic element 91 arranged to be hea-ted in accordance with thecurrent in the associated pole of to engage an insulating button 98 carried by the trip bar 94 to move the trip bar about its pivot upon the occurrence of an overload of. sufficient magnitude and duration to'ex the bimetallic element. Each of the magnetic devices comprises a lU-shaped magnetic member 99 arranged to have a ux induced therein by the current in the associated pole ofthe circuit breaker to attract an armaturel |00 which is pivoted on the pin 84a and extends across the three poles of the circuit breaker, the armature being provided with a iinger |8| for engaging an adjustable pin |82 on the tripping the circuit breaker and adapted Y trip bar 94 to move the trip bar about its pivot upon the occurrence of a sufiiciently high overload to cause the armature to be attracted by one or more of the magnets 99. f

In Fig. 2 of the drawings, the circuit breaker is shown in its closed circuit position with the tripping member 10 held in its latched position by the latch finger 12 of the trip device |5 against the force exerted by the tripping springs 1|. It will be observed that in this position of the circuit breaker the extending portions 15 on the tripping member 10 are disposed adjacent the operating pin 58 but out of engagement therewith.

Upon the occurrence of abnormal current conditions in the circuit breaker the trip bar 94 will be moved about its pivot by one or more of the thermal or the magnetic current responsive devices, depending upon the normal current conditions, to release the impact member 86 for operation in a counterclockwise direction about its pivot 86a by the springs 92 portion 88 oi.' the impact member will strike the latch plate 85 a hammerlike blow and move the latch nger 12 out of engagement with the yoke portion 13 of the tripping member 10. As soon as the latch finger 12 is disengaged from the yoke 13, the tripping member 10 will be operated in a clockwise direction about its pivot point by the tripping springs 1| and the extending portions 15 will engage the operating pin 58, the force exerted by the tripping springs 1| being of suiiicient magnitude to move the operating pin 58 against the force exerted by the overcenter spring devices to the position shown in Fig. 4, thereby breaking the toggle and operating the crossbar 39 and the movable contacts 23 to open circuit position. It will be observed that the tripping member carries a suitable target |03 which is arranged to cooperate with an aperture |04 in the insulated handle 53 to give a visual indication that the circuit breaker has been automatically tripped to open circuit-position.

To reclose the circuit breaker after it has been automatically tripped to open circuit position, it is necessary rst to move the handle 53 from the position shown in Fig. 4 downwardly to the position shown in Fig. 3. This movement of the handle 53 is effective to return the tripping member 1D to its latched position and to store tripping energy in the tripping springs 1|, the U-shaped operating member 52 being provided with shoulder portions |05 arranged to engage the extending portions 14 on the tripping member 10 to move the tripping member about its pivot 5| in a counterclockwise direction. The operating handle 53 may then be moved to its uppermost position shown in Fig. 2 to reclose the circuit breaker contacts in the manner heretofore described.

It will be apparent now that the arrangement of the tripping springs 1| and the tripping member 10 is such as to provide a very compact arrangement in which the operating elements are so nested together and overlapped as to reduce to a minimum the physical dimensions of the circuit breaker. Y

While I have shown a particular embodiment of my invention, it will be understood, of course, that I do not wish to be limited thereto, since many modications mayA be made and I, therefore, contemplate by the appended claims to cover any such modiiications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A circuit breaker comprising a pair of relatively movable contacts, an operating mechanism comprising a frame having spaced walls, 5 each of said walls including an elongate portion provided with a guide, manually operable means supported on said frame for operating one of said contacts between open and closed circuit positions, a pivoted tripping member having a l0 portion arranged to operate said one contact to open circuit position when said tripping member is moved to tripping position, a tripping spring disposed between saidelongate wall portions, a crossbar extending between said elongate por- 15 tions with its ends cooperating with said guides,

a portion of said crossbar engaging said spring, an operating strap connected between said crossbar and said tripping member, whereby said tripping spring biases said tripping member to tripping position and current responsive means normally latchin'g said tripping member out of tripping position arranged to release said tripping member for'operation by said tripping spring to operate said one contact to open circuit position upon the occurrence of predetermined abnormal current conditions.

2. A circuit breaker comprising a pair of relatively movable contacts, an operating mechanism comprising a frame having spaced walls, each of said walls including an elongate portion provided with a guide, manually operable means supported on said frame for operating one of said contacts between open and closed circuit positions, a pivoted tripping member having a portion arranged to operate said one contact to operi circuit position .when said tripping member is moved to tripping position, a tripping spring disposed between said elongate wall portions, a fixed crossbar supported by said elongate portions and engaging the end of said spring adjacent said tripping member, a movable crossbar extending between said elongate portions cooperating with said guides, said movable crossbar engaging the end of said spring remote from said tripping member, an operating strap extending along said elongate wall portions and connected between said movable crossbar and said tripping member whereby said tripping spring biases said tripping 50 member to tripping position and current responsive means normally latching said tripping member out of tripping position arranged to release said tripping member for operation by said tripping spring upon the occurrence of predetermined abnormal current conditions. 55

3. A circuit breaker comprising a pair of relatively movable contacts, an operating mechanism comprising a frame having spaced walls, each of said walls including an elongate portion provided with a guide, manually operable means supported on said frame for operating one of said contacts between open and closed circuit positions, a pivoted tripping member having a portion arranged to operate said one contact to open circuit position when said tripping member is moved to tripping position, a pair of spaced crossbars extending between said elongate wall portions, the one of said crossbars remote from said tripping member being slidably supported in said guides, a pair of operating straps extending along said elongate wall portions, each oi.' said straps having one end connected to said tripping member and its opposite end connected to said one crossbar, a

tripping spring disposed between said elongate walls with its respectiveends said spaced crossbars for biasing said tripping member to tripping position, current responsive means tripping position arranged to -release said tripping member for operation by said tripping spring upon the occurrence of predetermined abnormal current conditions. n

j y4. A circuit breaker comprising a pair of relav tively movable contacts, an operating mechanism comprising a frame having spaced wa1ls,-"each of y said walls including an elongate portion pro-y ing straps connected respectively to said extend- (ingportions on one side of said pivot point, said portions on the other side of said pivot point being n arranged to operate said one contact to open cirtripping spring disposed between said elongate walls with its respective endsengaging said spaced crossbars for biasing said tripping member to tripping positio and ciu'rent responsive means normally latching said tripping member out of 85 'tripping position`arranged to release said trippingmember for operation by said tripping spring toroperate said one contact to open circuit positionhrupon the occurrence of predetermined alinormal current conditions. 40 5. kA circuit breaker compl'isinga pir 0f relatively ,e movable contacts, an arc extinguishing tending along said chamber wall and a portion overhanging an end of said chamber, said elongate `portions having guides thereon, manually operable means supported on said overhanging I0 connected between said crossbar and said tripping member whereby said tripping spring biases saidtripping member to 'tripping position, and current responsive means normally latching said rence ofy predetermined abnormal current condif i tendingfalong said chamber wall and a portion frame portions for operating one of said contacts between open and closed circuit positions, a tripping member pivoted on said voverhanging portion and arranged to operate said one contact 40 to open circuit position when said tripping member is moved to tripping position, a pair of spaced crossbars extending between said elongate wall portions, the one of said crossbars remote to said .one crossbar, a tripping spring disposed 5o currence of predetermined abnormal current conditions.

8. A circuit breaker comprising a pair of relatively movable contacts, an arc ext chamber enclosing said contacts, an operating mechanism comprising a frame having spaced walls supported on a wall of said chamber, cach of said walls including an elongate portion extending along said chamber .wall and a portion overhanging an end of said chamber. said elongate portions having guides therein, manually operable means supported on said overhnging frame portions for voperating one of said contacts between open an closed circuit positions, a U-shaped tripping member pivoted on said frame, each leg of said U-shaped member having portions extending laterally thereof on yopposite sides of the pivot point, a pair of operating straps connected tween said elongate wall portions, the one of said crossbars remote from said tripping member being slidably supported in said vguides and connected to said operating straps, a tripping spring disposed between said elongate walls with its respective ends engaging said spaced crossbars for biasing said tripping member to tripping position, and currentl responsive means normally latching said tripping member out of tripping position arranged to release said tripping member for operation by said tripping spring to operate said one contact to open circuit position upon the occurrence of predetermined abnormal current conditions.

9. A circuit breaker comprising a pair of rela, tively movable contacts,l an operating mechanism comprising a frame having spaced walls, each of said walls including an elongate portion having a slot therein, an operating member pivotally mounted on said frame remote from said slot, a switch operating arm pivotally mounted adjacent said operating member, overcenter spring means connected between said operating member and said switch operating arm for moving said arm between open and closed circuit positions with a snap action, means operatively connecting said switch operating arm with'one of said contacts, a tripping member pivoted on said frame having a portion arranged to engage said switch operating arm to operate said one contact to open circuit position independently of said operating member when said tripping member is moved to tripping position, an operating strap connected to a portion of said tripping member,a pair of spaced crossbars extending between said elongate wall portions, the one of said crossbars remote from said tripping member being slidably supported in said slots and connected to said operating strap, a tripping spring disposed between said elongate walls with its respective ends engaging said spaced crossbars for biasing said tripping member to tripping position, and current responsive means normally latching said tripping member out of tripping position arranged to release said tripping member for operation by said tripping spring upon the occurrence of predetermined abnormal current conditions.

10. A circuit breaker comprising a pair of relatively movable contacts, an operating mechanism comprising a frame having spaced opposed walls, each of said walls including an elongate portion having a slot therein, a U-shaped operating member pivotally engaging said frame remote from said slot, a pair of spaced parallelarms having their adjacent ends pivctally engaging said frame within the legs of said U-shaped operating member, a pin carried by the other ends of said spaced arms, means operatively connecting said pin with one of said contacts, overcenter spring means connected between said pin and said operating member contact between open and closed circuit positions with a snap action, a U-shaped tripping member pivoted on said frame, each leg of said tripping member having portions extending laterally thereof on opposite sides of the pivot 25 point, a pair of operating straps connected respectively to said extending portions on one side of said pivot point, said portions on the other side of said pivot point being arranged to engager said pin for operating said one contact to open 30 circuit position against the force exerted by said overcenter spring means when said tripping member is moved to tripping position, a pair of spaced crossbars extending between said elongate wall portions, from said tripping member being slidably supported in said slots and connected to said operating straps, a tripping spring disposed between said elongate wall portions with its respective ends engaging said spaced crossbars for biasing said tripping member to tripping position, and current responsive means normally latching said tripping member out of tripping position arranged to release said tripping member for operation by said tripping spring upon the occurrence 4| of predetermined abnormal current conditions.

' LEON for operating said one 20 the one of said crossbars remote 35 

